Fibrous products



Patentec! Jan. 27, 1948 UNITED PATENT OFFICE and Richard Gilbert Perry,

Spondon, near Derby, England; Claude Bonard, administrator of said HenryDreyfus, deceased, assignors, by direct and mesne assignments, toCelanese Corporation of America, a corporation of Delaware No Drawing.Application February 4, 1944, Serial No. 521,136. In Great BritainJanuary 7, 1943 Section 1, Public Law 690, August s, 1946 Patent expiresJanuary 7, 1963 11 Claims. (Cl. 117-144) This invention relates tofibrous products, and in particular to the manufacture of cordage, forexample, ropes, twines and cords, of regenerated cellulose, Thisapplication is a continuation-inpart of our application S. No. 437,992,filed April 7, 1942, now abandoned.

We have found that the physical properties, and especially the wettenacity, handle and splicing properties, of materials of the kindreferred to above, can be greatly improved by impregnating them with ahot solution of a water resistant cellulose ester or ether in anon-aqueous liquid. The temperature of impregnation should be above theboiling point of Water and is preferably between about 120 C. and 150 C.By impregnation at such relatively high temperatures any moistureinitially present in the materials can be substantially removed andadequate penetration by the impregnating solution can readily beobtained.

By the process of the invention ropes, cords and like. products can bemade which are compact, have a desirable handle, can readily be splicedand are of considerably higher Wet tenacity than the untreated materialsor than materials treated with water-resistant esters or ethers ofcellulose at lower temperatures.

By a water-resistant ester or ether of cellulose is meant one which,when exposed dry to an atmosphere of 60% relative humidity at 21 C. doesnot absorb more than 3.5% of its weight of water. Among water-resistantesters or ethers of cellulose we have found ethyl cellulose to beparticularlysatisfactory.

As indicated above, the ethyl cellulose or other water-resistant esteror ether is applied to the material in solution in a non-aqueous liquid.Preferably a hydrophobe liquid, for example a high boiling liquidhydrocarbon or mixture of liquid hydrocarbons is employed as thesolvent. The best results have been obtained by impregnation attemperatures of about 120 to 150 C. Higher temperatures than this can beemployed but care must of course be taken not to work at a temperatureso high that the material treated, or the water-resistant ester orether, is damaged. Somewhat lower temperatures may also be employed, butthe temperature should be sufficiently high to secure thoroughpenetration of the solution into the material and substantial removal ofthe moisture content thereof, i. e., reduction of the moisture contentbelow 2% and preferably below 1% or even below 0.5%. The impregnationmay be efiected under atmospheric pressure or under super-atmosphericpressure.

In addition to the impregnation with the cellu-- lose derivative, thematerials may be subjected to further treatments, designed, for example,to improve their resistance to attack by micro-organisms and'theirwearing properties. A treatment which is particularly valuable is toapply to the material a heavy metal salt, e. g., a copper or a zincsalt, of naphthenic acid or other soap forming acid, for example stearicacid. Zinc naphthenate has been found particularly useful, not only inprotecting the rope against attack by micro-organisms, but also inenhancing its weather-resistance and abrasion resistance. Theapplication of other Water-insoluble metallic salts of carboxylic acidsto the materials, in conjunction with the cellulose derivativetreatment, also improves their wearing properties, rendering them moreresistant to abrasion. Apart from the heavy metal salts referred toabove, aluminium stearate has been found useful in improving theresistance to abrasion, All these salts can be applied to theimpregnated materials in solution in a hydrophobe liquid which is not asolvent for the cellulose derivative. Kerosene and other petroleumfractions are examples of suitable liquids. The best results howeverhave been obtained by applying such salts simultaneously with thecellulose derivative by the application of a hot solution of thecellulose derivative and metallic salt in a hydrophobe liquid. Theinvention also includes forming the metallic salts in situ on thematerials, for example by reaction between a sodium soap or othersoluble soap and a soluble salt of a metal which forms insoluble soaps.Improved resistance to abrasion is also conferred by the application ofcompositions containing linseed oil or other drying oils. Compositionscontaining lubricants such as mineral oils and graphite can also beemployed. A composition containing clay and graphite dispersed inkerosene to which a little linseed oil has been added considerablyenhances the resistance to abrasion. Another treatment which has beenfound to improve resistance to abrasion is to apply a compositioncontaining an' oil such as omega oil, and rubber latex in an aqueousdispersion containing ammonium stearate or other ammonium soap. Theammonium soap may subsequently be decomposed by heating the treatedrope.

The following examples illustrate the invention:

Example I The material treated is a three-stranded rope made, bysuccessive doubling operations with opposite directions of twist, fromregenerated cellulose yarn of tenacity about 6' gins. per denier whichhas been made by' the complete saponification of dry spun continuousfilament cellulose acetate yarn which has been stretched in steam or hotwater.

The rope is impregnated with a to 10% solution of ethyl cellulose inlight grade coal tar solvent naphtha at a temperature of about 120 to150 C. During the impregnation moisture isdriven off from the materialin the form of steam and to obtain the best results the rope shouldremain in contact with the impregnating bath until substantially thewhole of its moisture content has been so removed. The rope is thenremoved from the bath, freed from excess of the impregnating solution bytreatment iii a-entri iuge, and dried at about 80-90 C, I J v The driedrope contains about 5 to 10% of its original dry weight of ethylcellulose. It is su perior in wet-tenacity, water-resistance and handleto the untreated rope and has improved splicing properties;

Example II A rope treated according to Example I is subjected to furtherimpregnation with a cold solution of copper naphthenate in kerosene. Theimpregnation is efiected by running the rope through the bath containingthe solution of copper naphthenate at such a speed that the rope is incontact with the bath for about 30 seconds. The concentration of thenaphthenate in the bath is such that the treated material after dryingoff the kerosene, contains about 0.5 to 2% of its weight of copper inthe form of copper naphth nate.

The treated rope iS of high water-resistance and wet-tenacity and isalso improved in handle, Splicing properties, and durability whenexposed for long periods to tea water and to dafrip atmospheres.

Example HI The process is carried out as in Example 11 but substitutingzinc naphthenate for copper naphthenate. The treated ro'pe shows animprovemerit in properties similar to that of Example II, coupled withgreater resistance to abrasion.

Example IV The process is carried out as in Example I except that thebath contains in addition to the ethyl cellulose cop'per naphthenate insuch concentration that the rope, after removal of; the solvent,contains about 0.5 to 2% oi its weight of copper in the form of coppernaphthenate. This method involving the simultaneous application of thecopper naphthenate and the ethyl cellulose, is to be preferredto themethod described in Example II, as giving even higher water-resistanceand wet-tenacity.

E'itd'mple V The process is carried out as in Example IV butsubstituting zinc naphthenate for copper naphthenate. The treated ropeshows an improvement in properties similarto that of Example IV coupledwith greater resistance to abrasion.

Instead of solvent naphtha in the above examples toluene or any of thexylenes can be employed preferably at somewhat lower temperatures, forexample about 1 20" C. Lower temperatures still may be employed in allthe examples an active sol-ventfor the cellulose derivative. A

composition of considerable utility in increasing the abrasionresistance of the ropes of the invention can be made up as follows:

V Parts Water 1,898 Zinc oxide 20 Tannic acid 10 Boiled linseed oil 2Castor oil r 50 Pyridine I 10 the parts being by weight,

The composition resulting from mixing these constituents may be appliedto the rope after impregnatlon with the cellulose derivative and drying,by a bath treatment at a temperature of about 30 to 50 C. after whichrope is again dried.

A further treatment which may be applied to increase the abrasionresistance involves the applicatiori of graphite to the materialpreferably together with a drying oil. Thus for example the rope, afterimpregnation with the cellulose derivative followed by drying, may befurther impregnated with a solution of the following composition:

the parts being by weight. The impregnation may be efiected at ordinaryor elevated temperatures and the rope then dried.

The ropes or other products treated may be io'rnied from continuousfilament yarns, staple fibre yarns or stapilised 0r abraded yarns. Thefilaments or fibres of regenerated cellulose from which the yarns areformed may be produced by any suitable process, for example, by theviscose process, the cuprammonium process, or by the saponification offilaments or fibres of an organic ester of cellulose.

The process of the invention is of particular advantage in connectionwith the treatment of twines, cords and ropes composed of or containinghigh tenacity filaments or fibres of regenerated cellulose. Hightenacity filaments may be obtained by a wet-spinning process in thecourse of, which the filaments are stretched very con siderably, or, asindicated above, by the complete saponification of high tenacityfilaments 0r fibres of anrorganic ester of cellulose, such as can bemade for example by stretching filaments or fibres of the celluloseester of ordinary tenacity in steam, hot water, or an organicstretchassisting agent. Such high tenacity regenerated cellulosicfilaments or fibres may have a dry tenacity of 'over 2 gms. per denier,for example 2.5 to 3, '4, or even more than 5 gins. per denier. The wettenacity of such products is in general much lower than their -'drytenacity For some purposes this fact prevents full advantage being takenof the extraordinarily high dry tenacities of some of these products.The present invention, by enabling the wet tenacity to be considerablyincreased, greatly increases the utility of the products in question.The invention includes the treatment of twines, cords, ropes and otherproducts containing regenerated cellulosic filaments or fibres whetherof a normal, low, or high tenacity, in admixture with other textilematerials, of natural origin, for example, cotton, linen, jute, ramie,hemp, manilla, silk and wool, or of artificial origin, for examplecellulose esters or ethers, polymerised vinyl esters or ethers, orfilamentforming polyamides.

Ethyl cellulose has beeen instanced above as a water-resistant celluloseester or ether which can be employed with advantage in the process ofthe invention. Among other cellulose esters or ethers which can be soemployed are other waterresistant ethers of cellulose, for example,propyl cellulose, benzyl cellulose, butyl cellulose, ethyl butylcellulose, hexyl cellulose and ethyl hexyl cellulose; and celluloseesters, especially higher fatty acid esters, for example cellulosepropionate, cellulose butyrate, cellulose acetate-propionate, celluloseacetate-butyrate, cellulose stearate, cellulose palmitate, celluloseacetatestearate, cellulose acetate-palmitate, and cellulose laurate.There may be present in the composition containing the water-resistantester or ether, a plasticiser or softener therefor, and this should bewater-resistant. Plasticisers which are phosphoric esters have beenfound very suitable, for example, tricresyl phosphate, triphenylphosphate and tri-(monochlor butyl) phosphate. Other plasticisers thatmay be used include dimethyl phthalate, dimethoxy-ethyl phthalate andtri-(monochlorethyl) phosphate. Certain fixed vegetable oils have alsoproved satisfactory, e. g. castor oil, olive 011 and palm oil. Dryingoils such as linseed oil and cotton seed oil are less satisfactory, asare mineral oils.

The treatment may be applied at any convenient stage in the manufactureof the products. Thus, in the manufacture of ropes of regeneratedcellulose, the treatment may be applied to the filaments or fibres fromwhich the yarns are made, to the yarns themselves, to the strands intowhich the yarns are formed, or to the rope itself. It is preferred,however, to apply the impregnation with the cellulose ester or ether tothe rope as such, rather than to the components from which the rope isto be formed.

According to a modification of the invention, the materials are firsttreated so as substantially to remove their moisture content, forexample by immersion in a bath of hydrophobe liquid at a temperature ofabout 120 to 150 C., and are then impregnated with the cellulosederivative before any substantial moisture regain has occurred. When theprocess is modified in this way the impregnation may be effected atlower temperatures, e. g., 60 to 80 or 100 C.

According to a further modification of the invention the treatmentsdescribed above may be applied in the manufacture of ropes and likeproducts composed of or containing fibres of synthetic linear polymersother than regenerated cellulose, of lower water-resistance than theimpregnant. Thus, for example, ropes of an acetone-soluble celluloseacetate may be impregnated with ethyl cellulose, and rope of othercellulose esters or of cellulose ethers, may be impregnated withcellulose esters or ethers of higher water-resistance.

Having described our invention, what we desire to secure by LettersPatent is:

1. Process for the manufacture of cordage which comprises impregnatingcordage having-a basis of fibers of regenerated cellulose of tenacity atleast 2 grams per denier with a solution of a substance Selected fromthe class of water- -resistant esters of cellulose and water-resistantethers of cellulose, in a hydrophobe liquid at a. temperature of atleast 120 C., and evaporating said liquid from the impregnated material.

2. Process for the manufacture of cordage which comprises impregnatingcordage having a basis of continuous filaments of regeneratedcel 'luloseof tenacity at least 2 grams per denier with a solution of a substanceselected from the class of water-resistant ester of cellulose andwater-resistant ethers of cellulose, in a hydrophobe liquid at atemperature of at least 120 C., and evaporating said liquid from theimpregnated material. 1

3. Process for the manufacture of cordage which comprises impregnatingcordage having a basis of fibers of regenerated cellulose of tenacity atleast 2 grams per denier with a solution of a water-resistant ethylcellulose, in a hydrophobe liquid at a temperature of at least 120 0.,and evaporating said liquid from the impregnated material.

4. Process for the manufacture of cordage which comprises impregnatingcordage having a basis of continuous filaments of regenerated celluloseof tenacity at least 2 grams per denier with a solution of awater-resistant ethyl cellulose, in a hydrophobe liquid at a temperatureof at least 120 C., and evaporating said liquid fromv the impregnatedmaterial. 1

5. Process for the manufacture of cordage which comprises impregnatingcordage having abasis of continuous filaments of regenerated celluloseof tenacity at least 2 grams per denier with a solution of awater-resistant ethyl cellulose, in a liquid consisting substantially ofaromatic hydrocarbons boiling between and 160 C. at a temperature of atleast C., and evaporating said liquid from the impregnated material.

6. Process for the manufacture of cordage which comprises impregnatingcordage having a basis of fibers of regenerated cellulose of tenacity atleast 2 grams per denier with a solution of a heavy metal naphthenateand of a substance selected from the class of water-resistant esters ofcellulose and water-resistant ethers of cellulose, in a hydrophobeliquid at a temperature of at least 120 C., and evaporating said liquidfrom the impregnated material.

7. Process for the manufacture of cordage which comprises impregnatingcordage having a basis of fibers of regenerated cellulose of tenacity atleast 2 grams per denier with a solution of copper naphthenate and awater-resistant ethyl cellulose, in a hydrophobe liquid at a temperatureof at least 120 0., and evaporating said liquid from the impregnatedmaterial.

8. Process for the" manufacture of cordage which comprises impregnatingcordage having a basis of fibers of regenerated cellulose of tenacity atleast 2 grams per denier with a solution of zinc naphthenate and awater-resistant ethyl cellulose, in a hydrophobe liquid at a temperatureof at least 120 C., and evaporating said liquid from the impregnatedmaterial.

9;Prqcess. forv the; mamliaqtntg' @i: QQIYQQSQ: which comprisesimpregnating, qqxgggg haymg; basis: of fibers oiregenerated cgilulgge,of tegg ty at least 2 grams: per den-ierwiish a. smu u. n} a n e.selected frqm the las Q rwatsa avaia ia-tisig widli' fii resistantesters of 0511111056 and wag resls. M HENRY DBEYFUISI,

ethers of cellulose, in a hydr p ehe li u slh-a DQ79151 te er t e o atlest .1 C" eYfiPQIE-fii'lfi sa d. 3. 9MB! QA LB RT PERRY liquid from theimp e nated matexia impre mating said material with a .solubion Q15lgggvy 1Q, EEFEMQN (3TB? metal naphthenate a hydmphgm liming??? 71 12iellqw zas- 1FQ an: 9 rec rd in $.1

vaporating said liquid;

10. Prucess; for the manufacture i Q which comprises impregnatmg ard gfihavin a $1... 9 thi pat m UNITED STATES PATENTS basis: of fibers ofregenerated czil klbfifi 9i ienvci'ty 15 Number Name p p at-ieast2ygrams per 116M637: with a. 1591mm: in L, .1,,29A sgymour a J y ,8 1933water-resistant. ethyl "(561111 65 in :a. h dmphsabe 1,997, 57 Qhgpqk;

I ir". 16; 1935 liquid atia izemperature at at least 1.29. 16. e a w 2,5 ,013 Batgnan rating said liquid 'imm time imnre nated mane '2;,09, 5,3. 5 Qhgucg Nov. 9, 1937 rial, impregnating the said material'with a$9111: 29 2,Q9 8, 5$ 2 Champ Nqv. 9; L937 tion .of copper naphbhenafie:in :a. :hygiwophobg 2,1716%? Dyew :7 Oct, 31, 1939 liquid, andevapnraatm saidliquid- 2,395,219, Latpur June 181', 19 10 11. Processfor the manufactuve .of sewage 2 255439 Bgiclggl Juhg 10, 1 94}wifichcomprises impregnating cordagehaving a g,3 1,1'1% wlglit e ll egdbasis offfibextsof rqgeneraliedcelmlose of tenacity 2g 1,676,352 SegqeyJ iily l Q, 1928 of at least Zzgmms per denier with a. solution of2,108,804; Fipzgll Feb. 22, 1938 a water-resistantethylqcellulosminahydrophobe 2,330,938 8 001 1 Opt. 5, 1.943

